Jin X Q, Hugues-Salas E, Giddings R P, Wei J L, Groenewald J, Tang J M
School of Electronic Engineering, Bangor University, Dean Street, Bangor, LL57 1UT, UK.
Opt Express. 2011 Oct 10;19(21):20557-70. doi: 10.1364/OE.19.020557.
End-to-end real-time experimental demonstrations are reported, for the first time, of aggregated 11.25Gb/s over 26.4km standard SMF, optical orthogonal frequency division multiple access (OOFDMA) PONs with adaptive dynamic bandwidth allocation (DBA). The demonstrated intensity-modulation and direct-detection (IMDD) OOFDMA PON system consists of two optical network units (ONUs), each of which employs a DFB-based directly modulated laser (DML) or a VCSEL-based DML for modulating upstream signals. Extensive experimental explorations of dynamic OOFDMA PON system properties are undertaken utilizing identified optimum DML operating conditions. It is shown that, for simultaneously achieving acceptable BERs for all upstream signals, the OOFDMA PON system has a >3dB dynamic ONU launch power variation range, and the BER performance of the system is insusceptible to any upstream symbol offsets slightly smaller than the adopted cyclic prefix. In addition, experimental results also indicate that, in addition to maximizing the aggregated system transmission capacity, adaptive DBA can also effectively reduce imperfections in transmission channel properties without affecting signal bit rates offered to individual ONUs.
首次报道了在26.4公里标准单模光纤上实现11.25Gb/s聚合速率的端到端实时实验演示，该演示采用了具有自适应动态带宽分配（DBA）的光正交频分多址（OOFDMA）无源光网络（PON）。所演示的强度调制和直接检测（IMDD）OOFDMA PON系统由两个光网络单元（ONU）组成，每个光网络单元采用基于分布式反馈（DFB）的直接调制激光器（DML）或基于垂直腔面发射激光器（VCSEL）的DML来调制上行信号。利用确定的最佳DML工作条件，对动态OOFDMA PON系统特性进行了广泛的实验探索。结果表明，为了同时使所有上行信号的误码率（BER）可接受，OOFDMA PON系统具有大于3dB的动态ONU发射功率变化范围，并且系统的BER性能对任何略小于所采用循环前缀的上行符号偏移不敏感。此外，实验结果还表明，除了最大化聚合系统传输容量外，自适应DBA还可以有效降低传输信道特性中的缺陷，而不影响提供给各个ONU的信号比特率。
